1. Field of the Invention
The present invention is related to a grounding structure of a card reader, and especially to such a structure capable of effectively avoiding the integrated circuit of the card reader from damage by piercing of external electric waves, the structure is provided in the section between the integrated circuit of a circuit board and a housing with a plurality of electrically conductive areas formed of electrically conductive material, in order that the electrically conductive areas form a function of grounding to scatter the electric waves.
2. Description of the Prior Art
As shown in FIG. 1 which is a structural sectional view of a conventional card reader, wherein the whole card reader A includes a circuit board A2 in a housing A1 as a principal unit, The circuit board A2 is provided with a circuit connector A21 in order that the circuit connector A21 can be connected with a main circuit of an electric equipment (not shown) to form connecting of the card reader A with the main circuit, and to supply power for operation of the card reader A. The circuit board A2 is provided on the front surface thereof with an insertion slot A22 for insertion of a memory card; and an integrated circuit A23 is connected between the insertion slot A22 and the circuit connector A21 to control operation of the entire card reader A, and further to form the connection between the memory card and the main circuit.
When a normal card reader A is operated in cooperation with the connection between the main circuit and the memory card circuit, an electromagnetic effect will be induced by communicating of the electric current among the electric elements on the circuit board A2 of the card reader A; the electromagnetic effect will interfere with the normal operation of the circuit to influence the effect of operation of the entire circuit. Therefore, the structural design for the card reader A and the arrangement of the circuit thereof must be provided with a basic EMI preventing function in order to avoid the circuit in the memory card from interference of electric waves to influence accessing of data.
And more, for the convenience of insertion and drawing out for changing of the memory card, mostly a card reader has its insertion slot A22 allocated on the front surface of the housing A1, this surface also is provided with an opening A11 for passing of the memory card, thereby, the memory card can enter the card reader A to be fittingly inserted in the insertion slot A22. However, the opening A11 will also become an area losing the shielding of the housing A1, and is subjected to direct incidence of electric waves onto the circuit board A2 in the housing A1 through the opening A11 from the outside, and the electric waves will extend through the integrated circuit A23 to make it damaged and destroyed.
The grounding structure of a card reader of the present invention is provided in the section between the integrated circuit of a circuit board and a housing with a plurality of electrically conductive areas formed of electrically conductive material, the electrically conductive areas are connected with the grounding line of the circuit board in order that when the front surface of the housing of the card reader is subjected to an electric shock, the electrically conductive areas form a function of grounding to scatter the electric waves and to avoid the integrated circuit of the card reader from damage by piercing of external electric waves.
And the electrically conductive areas can be arranged at the position where the insertion slot is located on the circuit board, by the electromagnetic shielding action formed by the electrically conductive areas at the area of the insertion slot, the memory card in the insertion slot can further be subjected to an effect of EMI prevention.
The present invention will be apparent in its structural combination and the entire mode of operation thereof after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.